Barring the limitations listed in perl-5.8.0-RC3's perldoc threads, threads::shared and perlthrtut, what status is Perl's current threading implementation considered to be?

As of 5.6.1 it was experimental, but I cannot see any such warnings in 5.8.0. Are they now considered production quality, or just not quite so experimental as to be labelled as such?

I've read some of the earlier articles discussing fork() and Threads (now superceded by threads), but does Perl's current thread implementation offer the benefits of threading against just using fork() and spawning full child processes?

From a design and resource usage point of view, could someone please give some conditions where threading is considered preferable to fork()'ing?
I use fork a fair bit in order to process very large chunks of data in parallel, but I'd be interested to see if threading this sort of thing has any benefits.